In a work vehicle equipped with an HST traveling drive device configured by connecting a hydraulic motor to a hydraulic pump through a closed circuit connection, the hydraulic pump is directly connected to an engine. The behavior of such a vehicle is thus readily affected by any fluctuation in the engine rotation speed, which may cause the entire vehicle to pitch along the longitudinal axis.
As a means for addressing this issue, a technology whereby excessive acceleration is prevented when a large accelerator operation is performed to start moving from a standing stop or to accelerate a moving work vehicle equipped with an HST traveling drive device by limiting an increase rate per unit time of the actual accelerator operation quantity so as not to exceed a predetermined limit value (see PTL 1).